27th June 2010
So last night I stuck a dehumidifier in the above ground room and ran it along with the AC unit. Actually worked out great. Right now, it's 75F degrees and 42% RH, feels REALLY NICE in there. The dehumidifier pulled out about a gallon of water in the past 12 hours or so to get it from 60% RH to 42% (and keep it there). But when I turn off the dehumidifier, the RH starts rising pretty fast.
And, oh yeah, I'm not seeing a vapor barrier under the floor in that room, I'll surely have to add one... floor work will begin relatively soon. I hope that once the vapor barrier is in place, the room will hold the dehumidified air better so that the dehumidifier won't need to run nearly continuously.
So, having an AC and dehumidifier work together seems totally fine... set the AC to the desired temp and set the dehumidifier to the desired RH and they should run appropriately in order to condition the air as desired.
But, in my case anyway, there is one problem here... I need to now figure out a dehumidifier solution that is going to be efficient and QUIET. The ductless split AC is dead quiet... I do not know if anyone makes a dehumidifier that is designed to be quiet.
One thought is to look more into a "remote" dehumidifier that would sit in an adjacent room, with send and return ducted to the studio room, and a remote humidistat of course placed in the studio room. I did see one unit, a Santa Fe "Compact", that should work well in this way... and I do have an adjacent closet that is in a spot that will make it easy to add a water drain line to the outside. But if I try this, I'll need to deal with shock mounting the unit to kill any vibrations from the compressor, etc... also concerned about the degree of isolation I'll lose by adding two 4" or 6" holes in my multi-layered wall in order to add the in and out ducts.
Well, before I buy any special dehumidifiers, I need to fully complete the room (review the entire vapor barrier situation), and get all my gear in there and fire it up etc. It's possible that once my vapor barriers are fully in place, and the gear is in there running, the needs of the room will be a bit different.
It still puzzles me how this one room will rise to 62+% RH (whether the AC is on or not), but yet the rest of the building will stay at 50% RH or less, even when the AC is barely running or not running.